Heather,
 I tried the antibody (Oncogene's Cat:# IM42L, Ab-3) with various
antigen retrieval protocols on human FFPE blocks of breast carcinoma,
with no success. I resorted to rabbit polyclonal (RP1MT) from Triple
Point Biologics, Forest Grove, Oregon which worked well after heat
retrieval at pH 6.0 (Lhotak et al: Clin Experimental Metastasis
18:463-470, 2001).
I hope it helps,
Sincerely,

Sarka Lhotak

Hamilton Regional Cancer Centre
McMaster University
Hamilton, Ontario, Canada

lhotaks@mcmaster.ca